The present invention relates generally to integrated circuits (ICs), and more particularly to a system to improve magnetic shielding for IC chips and packages containing magnetically sensitive components.
Computers benefited from magnetic memories before semiconductor integrated circuit (IC) memory chips were available. Magnetic fields from currents in hand-woven wires stored binary data in the magnetic state of ferrite rings. However, the importance of magnetic memories has diminished when semiconductor ICs, which store orders of magnitude more data in orders of magnitude smaller structures with orders of magnitude greater speed, rose to prominence.
Recent discoveries have enabled the combination of semiconductor and magnetic data storage techniques, in IC memories such as magnetic random access memories (MRAMs). MRAM is a type of non-volatile memory with fast programming time and high density. When designed properly, MRAM provides a viable alternative to generic semiconductor ICs. However, these magnetic memories are susceptible to time-varying magnetic fields generated by some components in operating environments where significant power and current levels are required.
The shielding of IC chips, especially devices such as magnetic memories, from magnetic fields is therefore critical. A magnetic field can be viewed as a plurality of continuous, closed loops of field lines, which can be diverted by a magnetic shield. The magnetic shield can only protect an magnetically sensitive component inside it from external magnetic fields by collecting and concentrating an external magnetic field within the wall or shell of itself. In other words, a magnetic shield diverts a portion of loops or field lines to run within itself and therefore around a protected magnetically sensitive component.
Desirable in the art of IC designs are additional systems and methods that can improve magnetic shielding for IC chips and packages.